summaryrefslogtreecommitdiff
path: root/drivers/ata/pata_arasan_cf.c
blob: 371fd2c698b70ce1b283672c0c2472f8ce6ac263 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
/*
 * drivers/ata/pata_arasan_cf.c
 *
 * Arasan Compact Flash host controller source file
 *
 * Copyright (C) 2011 ST Microelectronics
 * Viresh Kumar <viresh.linux@gmail.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

/*
 * The Arasan CompactFlash Device Controller IP core has three basic modes of
 * operation: PC card ATA using I/O mode, PC card ATA using memory mode, PC card
 * ATA using true IDE modes. This driver supports only True IDE mode currently.
 *
 * Arasan CF Controller shares global irq register with Arasan XD Controller.
 *
 * Tested on arch/arm/mach-spear13xx
 */

#include <linux/ata.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/libata.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pata_arasan_cf_data.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/workqueue.h>

#define DRIVER_NAME	"arasan_cf"
#define TIMEOUT		msecs_to_jiffies(3000)

/* Registers */
/* CompactFlash Interface Status */
#define CFI_STS			0x000
	#define STS_CHG				(1)
	#define BIN_AUDIO_OUT			(1 << 1)
	#define CARD_DETECT1			(1 << 2)
	#define CARD_DETECT2			(1 << 3)
	#define INP_ACK				(1 << 4)
	#define CARD_READY			(1 << 5)
	#define IO_READY			(1 << 6)
	#define B16_IO_PORT_SEL			(1 << 7)
/* IRQ */
#define IRQ_STS			0x004
/* Interrupt Enable */
#define IRQ_EN			0x008
	#define CARD_DETECT_IRQ			(1)
	#define STATUS_CHNG_IRQ			(1 << 1)
	#define MEM_MODE_IRQ			(1 << 2)
	#define IO_MODE_IRQ			(1 << 3)
	#define TRUE_IDE_MODE_IRQ		(1 << 8)
	#define PIO_XFER_ERR_IRQ		(1 << 9)
	#define BUF_AVAIL_IRQ			(1 << 10)
	#define XFER_DONE_IRQ			(1 << 11)
	#define IGNORED_IRQS	(STATUS_CHNG_IRQ | MEM_MODE_IRQ | IO_MODE_IRQ |\
					TRUE_IDE_MODE_IRQ)
	#define TRUE_IDE_IRQS	(CARD_DETECT_IRQ | PIO_XFER_ERR_IRQ |\
					BUF_AVAIL_IRQ | XFER_DONE_IRQ)
/* Operation Mode */
#define OP_MODE			0x00C
	#define CARD_MODE_MASK			(0x3)
	#define MEM_MODE			(0x0)
	#define IO_MODE				(0x1)
	#define TRUE_IDE_MODE			(0x2)

	#define CARD_TYPE_MASK			(1 << 2)
	#define CF_CARD				(0)
	#define CF_PLUS_CARD			(1 << 2)

	#define CARD_RESET			(1 << 3)
	#define CFHOST_ENB			(1 << 4)
	#define OUTPUTS_TRISTATE		(1 << 5)
	#define ULTRA_DMA_ENB			(1 << 8)
	#define MULTI_WORD_DMA_ENB		(1 << 9)
	#define DRQ_BLOCK_SIZE_MASK		(0x3 << 11)
	#define DRQ_BLOCK_SIZE_512		(0)
	#define DRQ_BLOCK_SIZE_1024		(1 << 11)
	#define DRQ_BLOCK_SIZE_2048		(2 << 11)
	#define DRQ_BLOCK_SIZE_4096		(3 << 11)
/* CF Interface Clock Configuration */
#define CLK_CFG			0x010
	#define CF_IF_CLK_MASK			(0XF)
/* CF Timing Mode Configuration */
#define TM_CFG			0x014
	#define MEM_MODE_TIMING_MASK		(0x3)
	#define MEM_MODE_TIMING_250NS		(0x0)
	#define MEM_MODE_TIMING_120NS		(0x1)
	#define MEM_MODE_TIMING_100NS		(0x2)
	#define MEM_MODE_TIMING_80NS		(0x3)

	#define IO_MODE_TIMING_MASK		(0x3 << 2)
	#define IO_MODE_TIMING_250NS		(0x0 << 2)
	#define IO_MODE_TIMING_120NS		(0x1 << 2)
	#define IO_MODE_TIMING_100NS		(0x2 << 2)
	#define IO_MODE_TIMING_80NS		(0x3 << 2)

	#define TRUEIDE_PIO_TIMING_MASK		(0x7 << 4)
	#define TRUEIDE_PIO_TIMING_SHIFT	4

	#define TRUEIDE_MWORD_DMA_TIMING_MASK	(0x7 << 7)
	#define TRUEIDE_MWORD_DMA_TIMING_SHIFT	7

	#define ULTRA_DMA_TIMING_MASK		(0x7 << 10)
	#define ULTRA_DMA_TIMING_SHIFT		10
/* CF Transfer Address */
#define XFER_ADDR		0x014
	#define XFER_ADDR_MASK			(0x7FF)
	#define MAX_XFER_COUNT			0x20000u
/* Transfer Control */
#define XFER_CTR		0x01C
	#define XFER_COUNT_MASK			(0x3FFFF)
	#define ADDR_INC_DISABLE		(1 << 24)
	#define XFER_WIDTH_MASK			(1 << 25)
	#define XFER_WIDTH_8B			(0)
	#define XFER_WIDTH_16B			(1 << 25)

	#define MEM_TYPE_MASK			(1 << 26)
	#define MEM_TYPE_COMMON			(0)
	#define MEM_TYPE_ATTRIBUTE		(1 << 26)

	#define MEM_IO_XFER_MASK		(1 << 27)
	#define MEM_XFER			(0)
	#define IO_XFER				(1 << 27)

	#define DMA_XFER_MODE			(1 << 28)

	#define AHB_BUS_NORMAL_PIO_OPRTN	(~(1 << 29))
	#define XFER_DIR_MASK			(1 << 30)
	#define XFER_READ			(0)
	#define XFER_WRITE			(1 << 30)

	#define XFER_START			(1 << 31)
/* Write Data Port */
#define WRITE_PORT		0x024
/* Read Data Port */
#define READ_PORT		0x028
/* ATA Data Port */
#define ATA_DATA_PORT		0x030
	#define ATA_DATA_PORT_MASK		(0xFFFF)
/* ATA Error/Features */
#define ATA_ERR_FTR		0x034
/* ATA Sector Count */
#define ATA_SC			0x038
/* ATA Sector Number */
#define ATA_SN			0x03C
/* ATA Cylinder Low */
#define ATA_CL			0x040
/* ATA Cylinder High */
#define ATA_CH			0x044
/* ATA Select Card/Head */
#define ATA_SH			0x048
/* ATA Status-Command */
#define ATA_STS_CMD		0x04C
/* ATA Alternate Status/Device Control */
#define ATA_ASTS_DCTR		0x050
/* Extended Write Data Port 0x200-0x3FC */
#define EXT_WRITE_PORT		0x200
/* Extended Read Data Port 0x400-0x5FC */
#define EXT_READ_PORT		0x400
	#define FIFO_SIZE	0x200u
/* Global Interrupt Status */
#define GIRQ_STS		0x800
/* Global Interrupt Status enable */
#define GIRQ_STS_EN		0x804
/* Global Interrupt Signal enable */
#define GIRQ_SGN_EN		0x808
	#define GIRQ_CF		(1)
	#define GIRQ_XD		(1 << 1)

/* Compact Flash Controller Dev Structure */
struct arasan_cf_dev {
	/* pointer to ata_host structure */
	struct ata_host *host;
	/* clk structure */
	struct clk *clk;

	/* physical base address of controller */
	dma_addr_t pbase;
	/* virtual base address of controller */
	void __iomem *vbase;
	/* irq number*/
	int irq;

	/* status to be updated to framework regarding DMA transfer */
	u8 dma_status;
	/* Card is present or Not */
	u8 card_present;

	/* dma specific */
	/* Completion for transfer complete interrupt from controller */
	struct completion cf_completion;
	/* Completion for DMA transfer complete. */
	struct completion dma_completion;
	/* Dma channel allocated */
	struct dma_chan *dma_chan;
	/* Mask for DMA transfers */
	dma_cap_mask_t mask;
	/* dma channel private data */
	void *dma_priv;
	/* DMA transfer work */
	struct work_struct work;
	/* DMA delayed finish work */
	struct delayed_work dwork;
	/* qc to be transferred using DMA */
	struct ata_queued_cmd *qc;
};

static struct scsi_host_template arasan_cf_sht = {
	ATA_BASE_SHT(DRIVER_NAME),
	.sg_tablesize = SG_NONE,
	.dma_boundary = 0xFFFFFFFFUL,
};

static void cf_dumpregs(struct arasan_cf_dev *acdev)
{
	struct device *dev = acdev->host->dev;

	dev_dbg(dev, ": =========== REGISTER DUMP ===========");
	dev_dbg(dev, ": CFI_STS: %x", readl(acdev->vbase + CFI_STS));
	dev_dbg(dev, ": IRQ_STS: %x", readl(acdev->vbase + IRQ_STS));
	dev_dbg(dev, ": IRQ_EN: %x", readl(acdev->vbase + IRQ_EN));
	dev_dbg(dev, ": OP_MODE: %x", readl(acdev->vbase + OP_MODE));
	dev_dbg(dev, ": CLK_CFG: %x", readl(acdev->vbase + CLK_CFG));
	dev_dbg(dev, ": TM_CFG: %x", readl(acdev->vbase + TM_CFG));
	dev_dbg(dev, ": XFER_CTR: %x", readl(acdev->vbase + XFER_CTR));
	dev_dbg(dev, ": GIRQ_STS: %x", readl(acdev->vbase + GIRQ_STS));
	dev_dbg(dev, ": GIRQ_STS_EN: %x", readl(acdev->vbase + GIRQ_STS_EN));
	dev_dbg(dev, ": GIRQ_SGN_EN: %x", readl(acdev->vbase + GIRQ_SGN_EN));
	dev_dbg(dev, ": =====================================");
}

/* Enable/Disable global interrupts shared between CF and XD ctrlr. */
static void cf_ginterrupt_enable(struct arasan_cf_dev *acdev, bool enable)
{
	/* enable should be 0 or 1 */
	writel(enable, acdev->vbase + GIRQ_STS_EN);
	writel(enable, acdev->vbase + GIRQ_SGN_EN);
}

/* Enable/Disable CF interrupts */
static inline void
cf_interrupt_enable(struct arasan_cf_dev *acdev, u32 mask, bool enable)
{
	u32 val = readl(acdev->vbase + IRQ_EN);
	/* clear & enable/disable irqs */
	if (enable) {
		writel(mask, acdev->vbase + IRQ_STS);
		writel(val | mask, acdev->vbase + IRQ_EN);
	} else
		writel(val & ~mask, acdev->vbase + IRQ_EN);
}

static inline void cf_card_reset(struct arasan_cf_dev *acdev)
{
	u32 val = readl(acdev->vbase + OP_MODE);

	writel(val | CARD_RESET, acdev->vbase + OP_MODE);
	udelay(200);
	writel(val & ~CARD_RESET, acdev->vbase + OP_MODE);
}

static inline void cf_ctrl_reset(struct arasan_cf_dev *acdev)
{
	writel(readl(acdev->vbase + OP_MODE) & ~CFHOST_ENB,
			acdev->vbase + OP_MODE);
	writel(readl(acdev->vbase + OP_MODE) | CFHOST_ENB,
			acdev->vbase + OP_MODE);
}

static void cf_card_detect(struct arasan_cf_dev *acdev, bool hotplugged)
{
	struct ata_port *ap = acdev->host->ports[0];
	struct ata_eh_info *ehi = &ap->link.eh_info;
	u32 val = readl(acdev->vbase + CFI_STS);

	/* Both CD1 & CD2 should be low if card inserted completely */
	if (!(val & (CARD_DETECT1 | CARD_DETECT2))) {
		if (acdev->card_present)
			return;
		acdev->card_present = 1;
		cf_card_reset(acdev);
	} else {
		if (!acdev->card_present)
			return;
		acdev->card_present = 0;
	}

	if (hotplugged) {
		ata_ehi_hotplugged(ehi);
		ata_port_freeze(ap);
	}
}

static int cf_init(struct arasan_cf_dev *acdev)
{
	struct arasan_cf_pdata *pdata = dev_get_platdata(acdev->host->dev);
	unsigned long flags;
	int ret = 0;

	ret = clk_prepare_enable(acdev->clk);
	if (ret) {
		dev_dbg(acdev->host->dev, "clock enable failed");
		return ret;
	}

	ret = clk_set_rate(acdev->clk, 166000000);
	if (ret) {
		dev_warn(acdev->host->dev, "clock set rate failed");
		return ret;
	}

	spin_lock_irqsave(&acdev->host->lock, flags);
	/* configure CF interface clock */
	writel((pdata->cf_if_clk <= CF_IF_CLK_200M) ? pdata->cf_if_clk :
			CF_IF_CLK_166M, acdev->vbase + CLK_CFG);

	writel(TRUE_IDE_MODE | CFHOST_ENB, acdev->vbase + OP_MODE);
	cf_interrupt_enable(acdev, CARD_DETECT_IRQ, 1);
	cf_ginterrupt_enable(acdev, 1);
	spin_unlock_irqrestore(&acdev->host->lock, flags);

	return ret;
}

static void cf_exit(struct arasan_cf_dev *acdev)
{
	unsigned long flags;

	spin_lock_irqsave(&acdev->host->lock, flags);
	cf_ginterrupt_enable(acdev, 0);
	cf_interrupt_enable(acdev, TRUE_IDE_IRQS, 0);
	cf_card_reset(acdev);
	writel(readl(acdev->vbase + OP_MODE) & ~CFHOST_ENB,
			acdev->vbase + OP_MODE);
	spin_unlock_irqrestore(&acdev->host->lock, flags);
	clk_disable_unprepare(acdev->clk);
}

static void dma_callback(void *dev)
{
	struct arasan_cf_dev *acdev = (struct arasan_cf_dev *) dev;

	complete(&acdev->dma_completion);
}

static bool filter(struct dma_chan *chan, void *slave)
{
	chan->private = slave;
	return true;
}

static inline void dma_complete(struct arasan_cf_dev *acdev)
{
	struct ata_queued_cmd *qc = acdev->qc;
	unsigned long flags;

	acdev->qc = NULL;
	ata_sff_interrupt(acdev->irq, acdev->host);

	spin_lock_irqsave(&acdev->host->lock, flags);
	if (unlikely(qc->err_mask) && ata_is_dma(qc->tf.protocol))
		ata_ehi_push_desc(&qc->ap->link.eh_info, "DMA Failed: Timeout");
	spin_unlock_irqrestore(&acdev->host->lock, flags);
}

static inline int wait4buf(struct arasan_cf_dev *acdev)
{
	if (!wait_for_completion_timeout(&acdev->cf_completion, TIMEOUT)) {
		u32 rw = acdev->qc->tf.flags & ATA_TFLAG_WRITE;

		dev_err(acdev->host->dev, "%s TimeOut", rw ? "write" : "read");
		return -ETIMEDOUT;
	}

	/* Check if PIO Error interrupt has occurred */
	if (acdev->dma_status & ATA_DMA_ERR)
		return -EAGAIN;

	return 0;
}

static int
dma_xfer(struct arasan_cf_dev *acdev, dma_addr_t src, dma_addr_t dest, u32 len)
{
	struct dma_async_tx_descriptor *tx;
	struct dma_chan *chan = acdev->dma_chan;
	dma_cookie_t cookie;
	unsigned long flags = DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_SRC_UNMAP |
		DMA_COMPL_SKIP_DEST_UNMAP;
	int ret = 0;

	tx = chan->device->device_prep_dma_memcpy(chan, dest, src, len, flags);
	if (!tx) {
		dev_err(acdev->host->dev, "device_prep_dma_memcpy failed\n");
		return -EAGAIN;
	}

	tx->callback = dma_callback;
	tx->callback_param = acdev;
	cookie = tx->tx_submit(tx);

	ret = dma_submit_error(cookie);
	if (ret) {
		dev_err(acdev->host->dev, "dma_submit_error\n");
		return ret;
	}

	chan->device->device_issue_pending(chan);

	/* Wait for DMA to complete */
	if (!wait_for_completion_timeout(&acdev->dma_completion, TIMEOUT)) {
		chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
		dev_err(acdev->host->dev, "wait_for_completion_timeout\n");
		return -ETIMEDOUT;
	}

	return ret;
}

static int sg_xfer(struct arasan_cf_dev *acdev, struct scatterlist *sg)
{
	dma_addr_t dest = 0, src = 0;
	u32 xfer_cnt, sglen, dma_len, xfer_ctr;
	u32 write = acdev->qc->tf.flags & ATA_TFLAG_WRITE;
	unsigned long flags;
	int ret = 0;

	sglen = sg_dma_len(sg);
	if (write) {
		src = sg_dma_address(sg);
		dest = acdev->pbase + EXT_WRITE_PORT;
	} else {
		dest = sg_dma_address(sg);
		src = acdev->pbase + EXT_READ_PORT;
	}

	/*
	 * For each sg:
	 * MAX_XFER_COUNT data will be transferred before we get transfer
	 * complete interrupt. Between after FIFO_SIZE data
	 * buffer available interrupt will be generated. At this time we will
	 * fill FIFO again: max FIFO_SIZE data.
	 */
	while (sglen) {
		xfer_cnt = min(sglen, MAX_XFER_COUNT);
		spin_lock_irqsave(&acdev->host->lock, flags);
		xfer_ctr = readl(acdev->vbase + XFER_CTR) &
			~XFER_COUNT_MASK;
		writel(xfer_ctr | xfer_cnt | XFER_START,
				acdev->vbase + XFER_CTR);
		spin_unlock_irqrestore(&acdev->host->lock, flags);

		/* continue dma xfers until current sg is completed */
		while (xfer_cnt) {
			/* wait for read to complete */
			if (!write) {
				ret = wait4buf(acdev);
				if (ret)
					goto fail;
			}

			/* read/write FIFO in chunk of FIFO_SIZE */
			dma_len = min(xfer_cnt, FIFO_SIZE);
			ret = dma_xfer(acdev, src, dest, dma_len);
			if (ret) {
				dev_err(acdev->host->dev, "dma failed");
				goto fail;
			}

			if (write)
				src += dma_len;
			else
				dest += dma_len;

			sglen -= dma_len;
			xfer_cnt -= dma_len;

			/* wait for write to complete */
			if (write) {
				ret = wait4buf(acdev);
				if (ret)
					goto fail;
			}
		}
	}

fail:
	spin_lock_irqsave(&acdev->host->lock, flags);
	writel(readl(acdev->vbase + XFER_CTR) & ~XFER_START,
			acdev->vbase + XFER_CTR);
	spin_unlock_irqrestore(&acdev->host->lock, flags);

	return ret;
}

/*
 * This routine uses External DMA controller to read/write data to FIFO of CF
 * controller. There are two xfer related interrupt supported by CF controller:
 * - buf_avail: This interrupt is generated as soon as we have buffer of 512
 *	bytes available for reading or empty buffer available for writing.
 * - xfer_done: This interrupt is generated on transfer of "xfer_size" amount of
 *	data to/from FIFO. xfer_size is programmed in XFER_CTR register.
 *
 * Max buffer size = FIFO_SIZE = 512 Bytes.
 * Max xfer_size = MAX_XFER_COUNT = 256 KB.
 */
static void data_xfer(struct work_struct *work)
{
	struct arasan_cf_dev *acdev = container_of(work, struct arasan_cf_dev,
			work);
	struct ata_queued_cmd *qc = acdev->qc;
	struct scatterlist *sg;
	unsigned long flags;
	u32 temp;
	int ret = 0;

	/* request dma channels */
	/* dma_request_channel may sleep, so calling from process context */
	acdev->dma_chan = dma_request_channel(acdev->mask, filter,
			acdev->dma_priv);
	if (!acdev->dma_chan) {
		dev_err(acdev->host->dev, "Unable to get dma_chan\n");
		goto chan_request_fail;
	}

	for_each_sg(qc->sg, sg, qc->n_elem, temp) {
		ret = sg_xfer(acdev, sg);
		if (ret)
			break;
	}

	dma_release_channel(acdev->dma_chan);

	/* data xferred successfully */
	if (!ret) {
		u32 status;

		spin_lock_irqsave(&acdev->host->lock, flags);
		status = ioread8(qc->ap->ioaddr.altstatus_addr);
		spin_unlock_irqrestore(&acdev->host->lock, flags);
		if (status & (ATA_BUSY | ATA_DRQ)) {
			ata_sff_queue_delayed_work(&acdev->dwork, 1);
			return;
		}

		goto sff_intr;
	}

	cf_dumpregs(acdev);

chan_request_fail:
	spin_lock_irqsave(&acdev->host->lock, flags);
	/* error when transferring data to/from memory */
	qc->err_mask |= AC_ERR_HOST_BUS;
	qc->ap->hsm_task_state = HSM_ST_ERR;

	cf_ctrl_reset(acdev);
	spin_unlock_irqrestore(qc->ap->lock, flags);
sff_intr:
	dma_complete(acdev);
}

static void delayed_finish(struct work_struct *work)
{
	struct arasan_cf_dev *acdev = container_of(work, struct arasan_cf_dev,
			dwork.work);
	struct ata_queued_cmd *qc = acdev->qc;
	unsigned long flags;
	u8 status;

	spin_lock_irqsave(&acdev->host->lock, flags);
	status = ioread8(qc->ap->ioaddr.altstatus_addr);
	spin_unlock_irqrestore(&acdev->host->lock, flags);

	if (status & (ATA_BUSY | ATA_DRQ))
		ata_sff_queue_delayed_work(&acdev->dwork, 1);
	else
		dma_complete(acdev);
}

static irqreturn_t arasan_cf_interrupt(int irq, void *dev)
{
	struct arasan_cf_dev *acdev = ((struct ata_host *)dev)->private_data;
	unsigned long flags;
	u32 irqsts;

	irqsts = readl(acdev->vbase + GIRQ_STS);
	if (!(irqsts & GIRQ_CF))
		return IRQ_NONE;

	spin_lock_irqsave(&acdev->host->lock, flags);
	irqsts = readl(acdev->vbase + IRQ_STS);
	writel(irqsts, acdev->vbase + IRQ_STS);		/* clear irqs */
	writel(GIRQ_CF, acdev->vbase + GIRQ_STS);	/* clear girqs */

	/* handle only relevant interrupts */
	irqsts &= ~IGNORED_IRQS;

	if (irqsts & CARD_DETECT_IRQ) {
		cf_card_detect(acdev, 1);
		spin_unlock_irqrestore(&acdev->host->lock, flags);
		return IRQ_HANDLED;
	}

	if (irqsts & PIO_XFER_ERR_IRQ) {
		acdev->dma_status = ATA_DMA_ERR;
		writel(readl(acdev->vbase + XFER_CTR) & ~XFER_START,
				acdev->vbase + XFER_CTR);
		spin_unlock_irqrestore(&acdev->host->lock, flags);
		complete(&acdev->cf_completion);
		dev_err(acdev->host->dev, "pio xfer err irq\n");
		return IRQ_HANDLED;
	}

	spin_unlock_irqrestore(&acdev->host->lock, flags);

	if (irqsts & BUF_AVAIL_IRQ) {
		complete(&acdev->cf_completion);
		return IRQ_HANDLED;
	}

	if (irqsts & XFER_DONE_IRQ) {
		struct ata_queued_cmd *qc = acdev->qc;

		/* Send Complete only for write */
		if (qc->tf.flags & ATA_TFLAG_WRITE)
			complete(&acdev->cf_completion);
	}

	return IRQ_HANDLED;
}

static void arasan_cf_freeze(struct ata_port *ap)
{
	struct arasan_cf_dev *acdev = ap->host->private_data;

	/* stop transfer and reset controller */
	writel(readl(acdev->vbase + XFER_CTR) & ~XFER_START,
			acdev->vbase + XFER_CTR);
	cf_ctrl_reset(acdev);
	acdev->dma_status = ATA_DMA_ERR;

	ata_sff_dma_pause(ap);
	ata_sff_freeze(ap);
}

void arasan_cf_error_handler(struct ata_port *ap)
{
	struct arasan_cf_dev *acdev = ap->host->private_data;

	/*
	 * DMA transfers using an external DMA controller may be scheduled.
	 * Abort them before handling error. Refer data_xfer() for further
	 * details.
	 */
	cancel_work_sync(&acdev->work);
	cancel_delayed_work_sync(&acdev->dwork);
	return ata_sff_error_handler(ap);
}

static void arasan_cf_dma_start(struct arasan_cf_dev *acdev)
{
	u32 xfer_ctr = readl(acdev->vbase + XFER_CTR) & ~XFER_DIR_MASK;
	u32 write = acdev->qc->tf.flags & ATA_TFLAG_WRITE;

	xfer_ctr |= write ? XFER_WRITE : XFER_READ;
	writel(xfer_ctr, acdev->vbase + XFER_CTR);

	acdev->qc->ap->ops->sff_exec_command(acdev->qc->ap, &acdev->qc->tf);
	ata_sff_queue_work(&acdev->work);
}

unsigned int arasan_cf_qc_issue(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct arasan_cf_dev *acdev = ap->host->private_data;

	/* defer PIO handling to sff_qc_issue */
	if (!ata_is_dma(qc->tf.protocol))
		return ata_sff_qc_issue(qc);

	/* select the device */
	ata_wait_idle(ap);
	ata_sff_dev_select(ap, qc->dev->devno);
	ata_wait_idle(ap);

	/* start the command */
	switch (qc->tf.protocol) {
	case ATA_PROT_DMA:
		WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);

		ap->ops->sff_tf_load(ap, &qc->tf);
		acdev->dma_status = 0;
		acdev->qc = qc;
		arasan_cf_dma_start(acdev);
		ap->hsm_task_state = HSM_ST_LAST;
		break;

	default:
		WARN_ON(1);
		return AC_ERR_SYSTEM;
	}

	return 0;
}

static void arasan_cf_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
	struct arasan_cf_dev *acdev = ap->host->private_data;
	u8 pio = adev->pio_mode - XFER_PIO_0;
	unsigned long flags;
	u32 val;

	/* Arasan ctrl supports Mode0 -> Mode6 */
	if (pio > 6) {
		dev_err(ap->dev, "Unknown PIO mode\n");
		return;
	}

	spin_lock_irqsave(&acdev->host->lock, flags);
	val = readl(acdev->vbase + OP_MODE) &
		~(ULTRA_DMA_ENB | MULTI_WORD_DMA_ENB | DRQ_BLOCK_SIZE_MASK);
	writel(val, acdev->vbase + OP_MODE);
	val = readl(acdev->vbase + TM_CFG) & ~TRUEIDE_PIO_TIMING_MASK;
	val |= pio << TRUEIDE_PIO_TIMING_SHIFT;
	writel(val, acdev->vbase + TM_CFG);

	cf_interrupt_enable(acdev, BUF_AVAIL_IRQ | XFER_DONE_IRQ, 0);
	cf_interrupt_enable(acdev, PIO_XFER_ERR_IRQ, 1);
	spin_unlock_irqrestore(&acdev->host->lock, flags);
}

static void arasan_cf_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
	struct arasan_cf_dev *acdev = ap->host->private_data;
	u32 opmode, tmcfg, dma_mode = adev->dma_mode;
	unsigned long flags;

	spin_lock_irqsave(&acdev->host->lock, flags);
	opmode = readl(acdev->vbase + OP_MODE) &
		~(MULTI_WORD_DMA_ENB | ULTRA_DMA_ENB);
	tmcfg = readl(acdev->vbase + TM_CFG);

	if ((dma_mode >= XFER_UDMA_0) && (dma_mode <= XFER_UDMA_6)) {
		opmode |= ULTRA_DMA_ENB;
		tmcfg &= ~ULTRA_DMA_TIMING_MASK;
		tmcfg |= (dma_mode - XFER_UDMA_0) << ULTRA_DMA_TIMING_SHIFT;
	} else if ((dma_mode >= XFER_MW_DMA_0) && (dma_mode <= XFER_MW_DMA_4)) {
		opmode |= MULTI_WORD_DMA_ENB;
		tmcfg &= ~TRUEIDE_MWORD_DMA_TIMING_MASK;
		tmcfg |= (dma_mode - XFER_MW_DMA_0) <<
			TRUEIDE_MWORD_DMA_TIMING_SHIFT;
	} else {
		dev_err(ap->dev, "Unknown DMA mode\n");
		spin_unlock_irqrestore(&acdev->host->lock, flags);
		return;
	}

	writel(opmode, acdev->vbase + OP_MODE);
	writel(tmcfg, acdev->vbase + TM_CFG);
	writel(DMA_XFER_MODE, acdev->vbase + XFER_CTR);

	cf_interrupt_enable(acdev, PIO_XFER_ERR_IRQ, 0);
	cf_interrupt_enable(acdev, BUF_AVAIL_IRQ | XFER_DONE_IRQ, 1);
	spin_unlock_irqrestore(&acdev->host->lock, flags);
}

static struct ata_port_operations arasan_cf_ops = {
	.inherits = &ata_sff_port_ops,
	.freeze = arasan_cf_freeze,
	.error_handler = arasan_cf_error_handler,
	.qc_issue = arasan_cf_qc_issue,
	.set_piomode = arasan_cf_set_piomode,
	.set_dmamode = arasan_cf_set_dmamode,
};

static int __devinit arasan_cf_probe(struct platform_device *pdev)
{
	struct arasan_cf_dev *acdev;
	struct arasan_cf_pdata *pdata = dev_get_platdata(&pdev->dev);
	struct ata_host *host;
	struct ata_port *ap;
	struct resource *res;
	irq_handler_t irq_handler = NULL;
	int ret = 0;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -EINVAL;

	if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
				DRIVER_NAME)) {
		dev_warn(&pdev->dev, "Failed to get memory region resource\n");
		return -ENOENT;
	}

	acdev = devm_kzalloc(&pdev->dev, sizeof(*acdev), GFP_KERNEL);
	if (!acdev) {
		dev_warn(&pdev->dev, "kzalloc fail\n");
		return -ENOMEM;
	}

	/* if irq is 0, support only PIO */
	acdev->irq = platform_get_irq(pdev, 0);
	if (acdev->irq)
		irq_handler = arasan_cf_interrupt;
	else
		pdata->quirk |= CF_BROKEN_MWDMA | CF_BROKEN_UDMA;

	acdev->pbase = res->start;
	acdev->vbase = devm_ioremap_nocache(&pdev->dev, res->start,
			resource_size(res));
	if (!acdev->vbase) {
		dev_warn(&pdev->dev, "ioremap fail\n");
		return -ENOMEM;
	}

	acdev->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(acdev->clk)) {
		dev_warn(&pdev->dev, "Clock not found\n");
		return PTR_ERR(acdev->clk);
	}

	/* allocate host */
	host = ata_host_alloc(&pdev->dev, 1);
	if (!host) {
		ret = -ENOMEM;
		dev_warn(&pdev->dev, "alloc host fail\n");
		goto free_clk;
	}

	ap = host->ports[0];
	host->private_data = acdev;
	acdev->host = host;
	ap->ops = &arasan_cf_ops;
	ap->pio_mask = ATA_PIO6;
	ap->mwdma_mask = ATA_MWDMA4;
	ap->udma_mask = ATA_UDMA6;

	init_completion(&acdev->cf_completion);
	init_completion(&acdev->dma_completion);
	INIT_WORK(&acdev->work, data_xfer);
	INIT_DELAYED_WORK(&acdev->dwork, delayed_finish);
	dma_cap_set(DMA_MEMCPY, acdev->mask);
	acdev->dma_priv = pdata->dma_priv;

	/* Handle platform specific quirks */
	if (pdata->quirk) {
		if (pdata->quirk & CF_BROKEN_PIO) {
			ap->ops->set_piomode = NULL;
			ap->pio_mask = 0;
		}
		if (pdata->quirk & CF_BROKEN_MWDMA)
			ap->mwdma_mask = 0;
		if (pdata->quirk & CF_BROKEN_UDMA)
			ap->udma_mask = 0;
	}
	ap->flags |= ATA_FLAG_PIO_POLLING | ATA_FLAG_NO_ATAPI;

	ap->ioaddr.cmd_addr = acdev->vbase + ATA_DATA_PORT;
	ap->ioaddr.data_addr = acdev->vbase + ATA_DATA_PORT;
	ap->ioaddr.error_addr = acdev->vbase + ATA_ERR_FTR;
	ap->ioaddr.feature_addr = acdev->vbase + ATA_ERR_FTR;
	ap->ioaddr.nsect_addr = acdev->vbase + ATA_SC;
	ap->ioaddr.lbal_addr = acdev->vbase + ATA_SN;
	ap->ioaddr.lbam_addr = acdev->vbase + ATA_CL;
	ap->ioaddr.lbah_addr = acdev->vbase + ATA_CH;
	ap->ioaddr.device_addr = acdev->vbase + ATA_SH;
	ap->ioaddr.status_addr = acdev->vbase + ATA_STS_CMD;
	ap->ioaddr.command_addr = acdev->vbase + ATA_STS_CMD;
	ap->ioaddr.altstatus_addr = acdev->vbase + ATA_ASTS_DCTR;
	ap->ioaddr.ctl_addr = acdev->vbase + ATA_ASTS_DCTR;

	ata_port_desc(ap, "phy_addr %llx virt_addr %p",
		      (unsigned long long) res->start, acdev->vbase);

	ret = cf_init(acdev);
	if (ret)
		goto free_clk;

	cf_card_detect(acdev, 0);

	return ata_host_activate(host, acdev->irq, irq_handler, 0,
			&arasan_cf_sht);

free_clk:
	clk_put(acdev->clk);
	return ret;
}

static int __devexit arasan_cf_remove(struct platform_device *pdev)
{
	struct ata_host *host = dev_get_drvdata(&pdev->dev);
	struct arasan_cf_dev *acdev = host->ports[0]->private_data;

	ata_host_detach(host);
	cf_exit(acdev);
	clk_put(acdev->clk);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int arasan_cf_suspend(struct device *dev)
{
	struct ata_host *host = dev_get_drvdata(dev);
	struct arasan_cf_dev *acdev = host->ports[0]->private_data;

	if (acdev->dma_chan)
		acdev->dma_chan->device->device_control(acdev->dma_chan,
				DMA_TERMINATE_ALL, 0);

	cf_exit(acdev);
	return ata_host_suspend(host, PMSG_SUSPEND);
}

static int arasan_cf_resume(struct device *dev)
{
	struct ata_host *host = dev_get_drvdata(dev);
	struct arasan_cf_dev *acdev = host->ports[0]->private_data;

	cf_init(acdev);
	ata_host_resume(host);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(arasan_cf_pm_ops, arasan_cf_suspend, arasan_cf_resume);

#ifdef CONFIG_OF
static const struct of_device_id arasan_cf_id_table[] = {
	{ .compatible = "arasan,cf-spear1340" },
	{}
};
MODULE_DEVICE_TABLE(of, arasan_cf_id_table);
#endif

static struct platform_driver arasan_cf_driver = {
	.probe		= arasan_cf_probe,
	.remove		= __devexit_p(arasan_cf_remove),
	.driver		= {
		.name	= DRIVER_NAME,
		.owner	= THIS_MODULE,
		.pm	= &arasan_cf_pm_ops,
		.of_match_table = of_match_ptr(arasan_cf_id_table),
	},
};

module_platform_driver(arasan_cf_driver);

MODULE_AUTHOR("Viresh Kumar <viresh.linux@gmail.com>");
MODULE_DESCRIPTION("Arasan ATA Compact Flash driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);